Worldwide, approximately 500,000 cases of cervical cancer are diagnosed each year. Cancer of the cervix (cervical cancer) begins in the lining of the cervix and is the result of infection-induced mutations of cervical cells by the human papilloma virus (HPV). Early manifestations of persistent HPV infection are reflected when normal cervical cells gradually develop pre-cancerous changes that turn into cancer. Several terms are used to describe these pre-cancerous changes, including cervical intraepithelial neoplasia (CIN), squamous intraepithelial lesion (SIL), and neoplasia in situ, dysplasia.
There are 2 major types of cervical cancers: squamous cell carcinoma and adenocarcinoma. Cervical cancers and cervical precancers are classified by microscopic appearance. About 80%-90% of cervical cancers are squamous cell carcinomas, which are composed of cells that resemble the flat, thin cells called squamous cells that cover the surface of the endocervix. Squamous cell carcinomas most often begin where the ectocervix joins the endocervix.
The remaining 10%-20% of cervical cancers are adenocarcinomas. Adenocarcinomas are becoming more common in women born in the last 20 to 30 years. Cervical adenocarcinoma develops from the mucus-producing gland cells of the endocervix. Less commonly, cervical cancers have features of both squamous cell carcinomas and adenocarcinomas. These are called “adenosquamous carcinomas” or “mixed carcinomas.”
Improved therapies for cervical pre-cancer or dysplasia are urgently needed in the art.